(a) Field of the Invention
The present invention concerns the production of methane and carbon monoxide. It relates first to a process for the simultaneous production of methane and carbon monoxide from a treated gas essentially consisting of these two components and hydrogen, of the type in which the treated gas is cooled and partiallly condensed to constitute a vapor phase and a liquid phase, the liquid phase being expanded, vaporized, warmed and introduced into a column for withdrawing hydrogen; the liquid from the vat portion of this column is sub-cooled, expanded and divided into a plurality of flows; one of these flows is vaporized and warmed up to its dew temperature and is introduced into a column for the separation of CO and CH.sub.4, and another one of these flows is introduced into this same column at about its bulb temperature; and a cold input is supplied by means of an outside refrigerating cycle.
(b) Description of Prior Art.
Usually, there are two said flows, and consequently, the column for the separation of CO and CH.sub.4 is supplied at two locations. It is observed that the heat exchange diagram (enthapies in ordinates, temperatures in abscissae) of the countercurrent indirect heat exchanger which is used to produce the various coolings, vaporizations and warmings, is very opened in the hot portion, the temperature ranges being of the order of 15.degree. C. at the hot end. This corresponds to a relatively important irreversability of the process, and the invention aims at reducing this irreversability in order to make the entire treatment more economical with respect to energy consumption.